1. Field of the Invention
The present invention relates to a tactility providing apparatus and a manipulating device using the same and, more particularly, to a tactility providing apparatus for providing tactility information about an object for a tactile Organ of an operator when the object cannot be directly touched, and a manipulating device for performing an operation by transmitting tactility information about an object to the tactile organ of an operator using the tactility providing apparatus when the object cannot be directly touched.
2. Description of the Related Art
A manipulating device is designed to manipulate a microscopic object which cannot be directly touched by an operator or perform an operation in an extremely severe environment. This device is roughly constituted by two portions, i.e., a manipulating portion manipulated by the operator, and an operating portion, e.g., a manipulator, for directly performing an operation with respect to an object. The device allows the operator to indirectly manipulate the object. The following devices are available as such conventional manipulating devices.
FIGS. 34A and 34B show a conventional micromanipulator arranged for a microscope. FIG. 34A shows the overall arrangement. FIG. 34B is an enlarged view of part of the arrangement.
This enlarged view schematically shows a state wherein a microscopic cell such as a fertilized egg is fixed by suction with a pipet, and a reagent is injected into the cell with a needle, or a gene having different genetic information is injected in the cell (see Shikano, "Micromanipulation of Cells", Measurement and Control, Vol. 23, No. 9, pp. 32-38).
A piper 101c and a needle 101d are operably attached to the microscope. The piper 101c serves to fix a cell 101b, as an object, on a microscope main body 101a. The needle 101d is used to perform an operation with respect to the object.
Joysticks 101e and 101f for manipulating the pipet 101c and the needle 101d with the hands of an operator are mounted on the microscope main body 101a.
The operator performs an operation such as holding, incision, or injection by manipulating the piper 101c and the needle 101d with the joysticks 101e and 101f while observing the cell 101b through the microscope.
The above-mentioned operation is an indispensable support technique as a technique of manipulating cells, biopolymers, and the like in the recent study of biotechnology.
FIG. 35 shows a manipulator system for a conventional robot. This system is constituted by a slave arm 102c, a master arm 102f, fixing members 102g, and a control system 102h (see Tate and Sakaki, "Impedance Control Type Master/Slave System--Basic Principle and Application to Transmission Delay", Mechanical Technology Research Center Report, Vol. 46 (1992), No. 2, pp. 170-182). The slave arm 102c has a plurality of joints 102a with sensors, and a treatment section 102b. The master arm 102f has a plurality of joints 102d with sensors, and a treatment section 102e in correspondence with the arrangement of the slave arm 102c. The fixing members 102g serve to fix an arm of an operator to the master arm 102f so as to match the degree of freedom of movement of the master arm 102f to that of the arm of the operator. The control system 102h includes a signal processing circuit for matching the operation of the master arm 102f to that of the slave arm 102c.
When the operator fixes his/her arm to the master arm 102f and arbitrarily manipulates it, the operation state controls sensor information to drive the corresponding slave arm 102c.
The operation of the operator is then reproduced by the slave arm 102c through the master arm 102f. The operator receives an external force, received by the slave arm 102c, as a direct force through the master arm 102f.
Various types of manipulator systems have been proposed as well as manipulator systems for robots such as the one described above. Bilateral control methods, impedance control methods, and the like have been developed as methods of improving the operability of robots.
FIGS. 36A and 36B show a forceps as a medical instrument. FIG. 36A shows the overall arrangement. FIG. 36B is an enlarged view of a distal end portion of the forceps.
A forceps 721 is constituted by an insertion portion 722 to be inserted into a body cavity via the trachea or the like of a patient, a forceps portion 723 arranged on the distal end of the insertion portion 722, and a manipulating portion 724 arranged on the proximal end portion of the insertion portion 722.
The forceps portion 723 has a pair of pivotally supported forceps members 726a and 726b. The manipulating portion 724 is constituted by a stationary manipulating handle 727a fixed to the proximal end portion of the insertion portion and a movable manipulating handle 727b pivotally attached to the proximal end portion. These handles 727a and 727b serve to open/close the forceps members 726a and 726b.
When the forceps member 726b is pivoted, a manipulation shaft (not shown) in the insertion portion slides forward and backward. As a result, the forceps members 726a and 726b are opened/closed via a link mechanism (not shown).
The following problems are posed in the above-described conventional devices.
In the conventional device shown in FIGS. 34A and 34B, information indicating whether the operating portion is in contact with a sample in a proper state is only obtained as a two-dimensional image observed through the microscope. That is, information in the depth direction is only focus information about the image in spite of the fact that the operation of the operating portion is three-dimensional. For this reason, considerably high skills are required to determine, from such an image, a specific state in which the operating portion is in contact with the object. In practice, therefore, only a skilled person can use such a device.
Furthermore, objects to be studied in, for example, the medical and biotechnological fields are becoming smaller in size, from cells to intracellular substances.
With this trend, observation and manipulating portions for objects are also becoming smaller in size. With this reduction in size, a more sophisticated and accurate manipulation of a manipulator is required.
The robot manipulator shown in FIG. 35 is designed to allow an operator to recognize holding of an object by increasing the sense of resistance upon holding the object. In this case, however, information about the hardness/softness of the object and the like are not expressed in the master arm. That is, the device is not designed to reproduce a state wherein an ordinary person holds the object. Such a level of presentation of a sensation is sufficient for a rough operation such as conveying of an object. However, in a micromanipulator and the like which demand high-precision, minute operations and determinations, the level of presentation of a sensation described above is not sufficient for an improvement in operability by means of presentation of a sense of resistance or accurate recognition of an object to be held.
In manipulating the conventional forceps shown in FIGS. 36A and 36B, a delicate sense of manipulation cannot be obtained owing to its mechanism. For this reason, even a skilled operator is required to perform a very careful, accurate manipulation, e.g., recognizing the lever opening degree of the forceps and a peeled state of a tissue while monitoring an observation image through an abdominal cavity mirror. In practice, therefore, such an operation is limited to only highly skilled operators.
A problem similar to that in the operation of a forceps is assumed in the operation of an endoscope which is inserted into a body cavity to perform observation and medical treatment.
An inserting operation of a currently used endoscope is performed on the basis of only image information observed through the distal end portion and the above-mentioned insertion resistance. It is difficult to insert such an endoscope while predicting a pain felt by a patient when the outer wall of the endoscope is pressed against the inner wall of his/her organ. In addition, with the mechanical arrangement of a currently used endoscope, it is impossible for an operator to obtain information about the correlation between the level of pressure and the pain felt by a patient, i.e., information indicating a specific degree of pressure at which a patient feels a pain, as manipulation information.
As described above, when the above-described conventional manipulating devices are manipulated, operators cannot recognize a specific state in which the operating portion is in contact with a tissue, or cannot obtain information indicating a force with which an object is held. That is, the conventional devices cannot allow operators to recognize a contact or held state or obtain various types of contact information such as the surface roughness and surface temperature of an object.
In the conventional devices, tactility information and held state information about an object and various types of tactility information such as the surface roughness and surface temperature of an object are not fed back to operators. For this reason, a minute, accurate manipulation based on the tactility of a human being cannot be performed.